3 ms·

I'm not a physicist, but from my understanding, light doesn't move at any speed from its own point of view. Its actually instant. From creation to absorption

I'm not a physicist, but from my understanding, light doesn't move at any speed from its own point of view. Its actually instant. From creation to absorption (or dissolution?), there's no delay from its point of view. Fast or slow has no meaning for light. We view things as having speed because mass slows things down from being instant. Am I correct?

gioi 11y ago
I'm not a physicist either. As a student, some years ago I asked my physics teacher if this conception was right, but I only got pretty elusive answers. It turns out that general relativity and quantum mechanics are not 100% coherent on this point. I suggest you to read this short, a-bit-technical-but-not-too-much essay on the problem: http://quasars.org/photon.txt http://quasars.org/photon.txt
redacted 11y ago
(Disclaimer: I am a physicist, but this is not my area of expertise at all. Happy to be corrected here). Relativity is, like quantum mechanics, a fairly simple concept with incredibly complex implications and edge cases. The easiest intuitive explanation of relative time I have found is the following: - Assume our space time/universe is a 4D vector space. Three spatial dimensions, one time. - Everything has a 4D vector which describes movement through this 4D space-time {x, y, z, t} - The length/magnitude of this vector is fixed at the speed of light, c - Normalize the dimensions of our 4D space as following: if we are not moving at all (x = y = z = 0) the vector points entirely in time our vector is {0, 0, 0, c} and, in our frame of reference, time moves as normal - "one second per second". - Now, as we go faster and faster this vector no longer points purely in time. In the extreme case where the vector sum of the x, y, z (3D spatial component) is c, the time component t will be zero. This is why our photon does not experience time passing - it moves through space at c, so cannot move through time at all. For the 3D velocities we normally experience we do not move in space fast enough to affect motion through time appreciably. Even the GPS corrections for relativity mostly arise due to Earth's gravity well distorting local space-time geometry, although their high velocity does contribute. Objects with mass cannot be accelerated to c under our current understanding of relativity because kinetic energy diverges (approximately 1/sqrt(1-v^2/c^2)) - reaching speed of light would require infinite energy.

gioi 11y ago

I'm not a physicist either. As a student, some years ago I asked my physics teacher if this conception was right, but I only got pretty elusive answers. It turns out that general relativity and quantum mechanics are not 100% coherent on this point. I suggest you to read this short, a-bit-technical-but-not-too-much essay on the problem: http://quasars.org/photon.txt http://quasars.org/photon.txt

redacted 11y ago

(Disclaimer: I am a physicist, but this is not my area of expertise at all. Happy to be corrected here). Relativity is, like quantum mechanics, a fairly simple concept with incredibly complex implications and edge cases. The easiest intuitive explanation of relative time I have found is the following: - Assume our space time/universe is a 4D vector space. Three spatial dimensions, one time. - Everything has a 4D vector which describes movement through this 4D space-time {x, y, z, t} - The length/magnitude of this vector is fixed at the speed of light, c - Normalize the dimensions of our 4D space as following: if we are not moving at all (x = y = z = 0) the vector points entirely in time our vector is {0, 0, 0, c} and, in our frame of reference, time moves as normal - "one second per second". - Now, as we go faster and faster this vector no longer points purely in time. In the extreme case where the vector sum of the x, y, z (3D spatial component) is c, the time component t will be zero. This is why our photon does not experience time passing - it moves through space at c, so cannot move through time at all. For the 3D velocities we normally experience we do not move in space fast enough to affect motion through time appreciably. Even the GPS corrections for relativity mostly arise due to Earth's gravity well distorting local space-time geometry, although their high velocity does contribute. Objects with mass cannot be accelerated to c under our current understanding of relativity because kinetic energy diverges (approximately 1/sqrt(1-v^2/c^2)) - reaching speed of light would require infinite energy.